Triple-valve device.



F. B. FARMER.

TRIPLE VALVE DEVICE.

APPLICATION FILED MAY 6. 1909.

1,1 14,741. Patented 001;. 27, 1914.

WITNESSES INVENTOR THE NORRIS PEYERS 60.. PHOTO LITHO.. WASHINGTON. D.c.

UNIT D sTATEs P TENT OFFICE,

FRED B. FARMER, on ST, PAUL, MINNnsoTA, AssreNoa To THE WESTINGHOUSE AinBRAKE COMPANY, or PITTSBURGH, PENNSYLVANIA, oonronATIoN or PENN-sYLvANIA.

TRIPLE-VALVE DEVICE.

Specification of Letters Patent. Patented Oct. 2'7, 1914.

Application filed May 6, 1909; Serial No. 494,392. I

To all whom it may concern:

Be it known that I, FRED B. FARMER, a citizen of the United States,residing at St. Paul in the county of Ramsey and State of Minnesota,have invented new and useful Improvements in Triple-Valve Devices, ofwhich the following is a specification.

This invention relates to triple valve devices, and more particularly tothose known as the quick action type. With this class of triple valvedevices as at present constructed, it occasionally happens that, byreason of a sticky triple piston or other cause, the triple valve partswill make the full traverse to emergency position upon a servicereduction in train pipe pressure and thereby cause an undesiredoperation of the well known serial quick action feature to shift all theother triple valves in the train to emergency position when only aservice application of the brakes is desired. This often results inannoying delays and sometimes causes accidents.

The principal object of my invention is to provide means for preventingfull traverse of the triple valve parts to emergency position upongradual or service reductions in train pipe pressure.

For this purpose my improvement consists in providing means adapted torestrict the flow of air from the triplevalve piston when only a gradualreduction in train pipe pressure is made, so that air in the triplepiston chamber acts on the dash-pot principle to retard the movement ofthe piston and thereby prevent the same from making full traverse toemergency position, said means being operated, however, by a suddenreduction in train pipe pressure to open a free communication from thetriple valve piston to the train pipe, so as to permit an emergencyoperation of the triple valve when desired.

The single figure in the accompanying drawing is an elevational view,partly in section, of a standard quick action triple valve device,showing my improvement applied thereto.

As illustrated in the drawing, the triple valve device is of the usualstandard construction, comprising a casing 1, triple valve piston 2,main slide valve 3, and graduating valve 4. The seat of the main slidevalve is provided with the usual brake cylinder port 5, exhaust port 6,and port ,7, leading to the port 9, quick action emergency piston, whichit is not deemed necessary to show, as its operation is well understoodby those familiar with air brakes.

The main slide valve is provided with the usual exhaust cavity 8,graduating or service application port 11.

The means for preventing undesired quick action is preferably located inthe triple valve cap section 12 and comprises a movable port lOandemergency abutment 13 contained in a piston chamber 14, into which trainpipe passage 15 opens. The chamber 16 at the opposite face of theabutment 13 has a restricted communication with the train pipe through asmall port17 in the abutment 13, and a spring 18 acts on said abutmentand tends to maintain the same in its inner position. The abutment 13 isconnected to a piston valve 19 operating in piston chamber 20 andadapted to control communication between a passage 21 leading to thetrain pipe passage 15 and triple valve piston chamber 22. vThe pistonvalve 19 is adapted to seat in its inner positionon a gasket'ring 23 soasto prevent any leakage from the piston chamber 22 to the .train pipe.A port 24 forms a restricted communication from the piston chamber 22 tothe train pipe passage 21 and is of such size as to permit of gradualreductions in pressure in the piston chamber 22 at a rate sufficient foreffecting the movement of the triple valve'partsto service applicationposition under normal conditions and should be slightly larger than thefeed groove aroundthe triple valve piston. A large passage 25 also formsa communication from the train pipe to the piston chamber 22 and thispassage contains a check valve 26 adapted to permit free flow of airfrom the train pipe to the piston chamber but preventing back flow fromthe piston chamber.

In operation, fluid under pressure supplied to the train pipe flowsthrough passage 25 past check valve 26 into piston chamber 22 and thencethrough the usual feed groove around the triple valve piston 2 chargingthe auxiliary reservoir to normal standard pressure in the usual manner.Air also flows 'to the outer face of themovable abutment 13 andequal-izes through the restricted port 17 into the chamber 16, so thatthe pressures upon the opposite sides of said abutment becomeequal tothe standard pressure and the spring 18 then maintains the abutment andthe valve 19 in the inner position closing communication between thepistonchamber 22 and the train pipe passage 21. Upon making a gradualreduction in train pipe pressure to effect a service application of thebrakes, air can way of the restricted port 24, the passage 25 beingclosed by the check valve 26 and the passage 21 by the valve 19. Ordi-cnarily, the triple valve parts will then move to service applicationposition in response to the reduction in pressure produced through theport 2%. But if the piston 2 should stick, the pressurein piston chamber22 will then continue to reduce until a sufficient. difierential ofpressure is produced to start the piston. "Withthe ordinary standardtriple valve, under such conditions, the stickytriple 'alve pistonhaving once been started, is very apt to shift over to emergencyposition, but with the present construction, as the only outlet "for airfrom the piston chamber 22 is throughthe restricted port 2 1, themovement of the piston 2 will be resisted by the air pressure in thepiston chamber 22, and thispressure consequently acts on the well knowndash-pot principle to prevent rapid or excessive movement of the piston.When the triple valve piston has moved out to service applicationposition, as limited in the usualmanner by the graduating stem 27, thespring 18 serving as the graduating spring, communication is opened fromthe auxiliary reservoir tothe brake cylinder throughports 9 and 5, andthe consequent reduction in auxiliary reservoir pressure by flow of airto the brake cylinder to gether with the resistance of the spring 18then checks further outward movement of the triple valve piston. \Vhengradual reductions .in train pipe pressure are made,

fluid in chamber 16 will flow back tothe train pipe through restrictedport 17 with sufiicient rapidity to maintain the opposing fluidpressures on the abutment 13 substantially equal, and consequently saidabutment and valve 19 will be maintained in their inner, closedpositionby the spring 18. The brakes maybe readily released by increasing thetrain pipe pressure, the large release passage 25 permitting an ampleflow of air to the triple valve piston, so that the same is at onceshifted to release position. When an emergency or sudden reduction intrain pipe pressure is made, the port 17 is so restricted that the fluidpressure from chamber 16 cannot flow back into the train pipe withsuflicient rapidity to maintain equilibrium of pressures on the abutment13 and consequently, the pressure in said chamber soon preponderatingover the train pipe pressure, the abutment is thereby shifted outwardly,causing the valve 19 to move from its seat 23 and open the large trainpipe passage 21 to only. flow from the piston chamber 22. by

the piston chamber 22. A rapid reduction in pressure in piston chamber22 then follows, and the triple valve piston is immediately shifted tothe extreme emergency position, thus operating the quick actionmechanism and producing an emergency application of the brakes. As thefluid pressures on piston 13 equalize, the spring 18 returns the partsto their normal closed position.

It will now be apparent that I have provided means whereby movement ofthe triple valve parts to emergency position is prevented when a gradualreduction in train pipe pressure is made, while retainingthe usualfacility of operation of the triple valve for all normal movements.

Having now described my invention, what 1 claim as new and desire tosecure by Let ters Patent, is

1. In a fluid pressure brake, the combination with a triple valve devicecomprising valve means for controlling the brakes and a piston containedin a piston chamber for actuating said valve means, of a restricted portcommunicating directly with said chamber for limiting the flow of airfrom said piston chamber to the train pipe to prevent sudden movement ofsaid piston upon a gradual reduction in train pipe pressure.

In a fluid pressure brake, the combina tion with a triple valve devicecomprising valve means for controlling the brakes and a piston containedin a piston chamber for actuating said valve means upon a gradualreduction in train pipe pressure to effect a partial traverse and upon asudden reduction in train pipe pressure to effect a full traverse, of arestricted port leading directly into said chamber fo 1 restricting theflow of air from said piston chamber to the train pipe when a gradualreduction in train pipe pressure is made, to thereby prevent fulltraverse of said piston.

3. In a fluid pressure brake, the combination with a triple valve devicecomprising valve means for controlling the brakes and a piston containedin a piston chamber for actuating said valve meansupon a gradualreduction in train pipe pressure to effect a partial traverse and upon asudden reduction in train pipe pressure to effect a full traverse, of arestricted port connecting the piston chamber with the usual triplevalve cap chamber for limiting the rate of flow of air from said pistonchamber to the train pipe when a gradual reduction in train pipepressure is made to prevent full traverse of said piston and meansoperating upon a sudden reduction in train pipe pressure to open acommunication for permitting free flow of air from said piston chamber.

4. A quick action triple valve device comprising a valve and pistonoperating upon a gradual reduction in train pipe pressure to make apartial traverse in service applications and upon a sudden reductionintrain pipe pressure to make a full traverse in emergency applications, aconstantlyv open restricted passage from the piston to the train pipefor limiting the flow of air from said piston during a gradual reductionin train pipe pressure, a second passage forming a communication betweensaid piston and train pipe, a valve for controlling said second passageand I a movable abutment subject to the opposing pressures of the trainpipe and a chamber for maintaining said second passage closed during agradual reduction in train pipe'pressure, said abutment being operatedupon a sudden reduction in train pipe pressure for opening said valve.

5. A quick action triple valve device comprising a valve and pistonoperating upon a gradual reduction in train pipe pressure to make apartial traverse in service applications and upon a sudden reduction intrain pipe pressure to make a full traverse in emergency applications, avalve for controlling communication from said piston to the train pipe,a movable abutment, subject to the opposing pressures of the train pipeand a chamber having a restricted communication with the train pipe, forcontrolling said valve.

6. A quick action triple valve device comprising a valve and pistonoperating upon a gradual reduction in train pipe pressure to make apartial traverse in service applications and upon a sudden reduction intrain pipe pressure to make a full traverse in emergency applications, aconstantly open restricted passage for permitting a limited flow of airfrom the piston to the train pipe, a valve for controlling asecondpassage from the piston to the train pipe, a spring tending to closesaid valve, and a movable abutment, subject to the opposing pressures ofthe train pipe and a chamber having a restricted communication with thetrain pipe, for operating said valve upon a sudden reduction in trainpipe pressure.

7. In a quick action triple valve device, the combination with valvemeans and a piston adapted upon a gradual reduction in train pipepressure to make a partial traverse in service applications and upon asudden reduction in train pipe pressure to make full traverse inemergency applications, of means adapted during gradual reductions intrain pipe pressure to restrict the flow of air from said piston to thetrain pipe and operated by a sudden reduction to any hand.

open communication for permitting free flow of air from said piston tothe train pipe and a passage adapted to supplyair to said piston inreleasing the brakes and provided with a check valve for preventing flowof air from the piston to the train pipe.

8. In a triple valve device, the combination with valve means and apiston operating upon a reduction in train pipe pressure for supplyingair to the brake cylinder, of a free open restricted passage from thepiston to the train pipe adapted to permit a gradual reduction inpressure upon said piston and a release passage for permitting the freeadmission of air from the train pipe to said piston in releasing thebrakes and provided with a check valve for preventing flow of air fromthe piston to the train pipe.

9. In a triple valve of an automatic air brake apparatus, thecombination with the triple valve piston and cylinder in which itoperates having a communication with the train pipe of relatively smallcapacity, and a connecting passage of larger capacity between saidcylinder and train pipe, and a valve controlling the said passage; andan actuating piston for said valve subjected to train pipe pressure atone s ide, and at the opposite side to pressure in an equalizing chamberhaving a communication of relatively small capacity with the train pipe,whereby said piston is actuated by the pres sure in said equalizingchamber to open said valve when train pipe pressure is suddenly reduced.

10. In a triple valve of an automatic air brake apparatus, the triplevalve piston and cylinder in which it operates, in free communicationwith the auxiliary reservoir at one end, and having a closure at theother end and a relatively small communication with the train pipe, anda relatively large valve controlled communication, whereby when saidvalve controlled communication is closed, movement of said piston bypreponderance of auxiliary reservoir pressure increases the pressure inthe cylinder at the other side of the piston and is checked thereby, andthereafter controlled by reduction of pressure by flow of air throughsaid small communication.

In testimony whereof I have hereunto set FRED B. FARMER. f Witnesses S.R. MoMAsTERs, JNo. P. LARKIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G. 5

